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Title: Method of making bonded or sintered permanent magnets

Patent ·
OSTI ID:868901

An isotropic permanent magnet is made by mixing a thermally responsive, low viscosity binder and atomized rare earth-transition metal (e.g., iron) alloy powder having a carbon-bearing (e.g., graphite) layer thereon that facilitates wetting and bonding of the powder particles by the binder. Prior to mixing with the binder, the atomized alloy powder may be sized or classified to provide a particular particle size fraction having a grain size within a given relatively narrow range. A selected particle size fraction is mixed with the binder and the mixture is molded to a desired complex magnet shape. A molded isotropic permanent magnet is thereby formed. A sintered isotropic permanent magnet can be formed by removing the binder from the molded mixture and thereafter sintering to full density.

Research Organization:
Ames Laboratory (AMES), Ames, IA; Iowa State Univ., Ames, IA (United States)
DOE Contract Number:
W-7405-ENG-82
Assignee:
Iowa State University Research Foundation, Inc. (Ames, IA)
Patent Number(s):
US 5240513
Application Number:
07/593,943
OSTI ID:
868901
Country of Publication:
United States
Language:
English

References (6)

New material for permanent magnets on a base of Nd and Fe (invited) journal March 1984
Permanent magnet materials based on the rare earth-iron-boron tetragonal compounds journal September 1984
Hot‐pressed neodymium‐iron‐boron magnets journal April 1985
The metal injection molding process comes of age journal August 1989
Processing of Neodymium-Iron-Boron melt-spun ribbons to fully dense magnets journal September 1985
Iron‐based rare‐earth magnets (invited) journal April 1985